Bimetallic complex of the type [Cu(tren)(NCS)]₄[Mn(NCS) ₆]: A hydrogen bonded network structure

MnCl₂ • 4H₂O, Cu(NO₃)₂ • 3H₂O, tris(2-aminoethyl)amine (tren) and NH₄NCS in a 1:4:4:10 molar ratio in aqueous solution results a bimetallic compound of the type [Cu(tren)(NCS)]₄[Mn(NCS)₆] (1) which has been characterized by microanalytical, physicochemical, spectroscopic and magnetic results. The structure of the complex is determined by X-ray diffraction study. Some pertinent crystal data are: monoclinic, space group P21/c, a = 11.0442(9) Å, b = 14.4923(12) Å, c = 19.2505(16) Å, β = 91.95(10)°, and Z = 4. The crystal structure consists of a hydrogen bonded 3D network of [Cu(tren)(NCS)]⁺ and [Mn(NCS)₆]^4- ions. Manganese(II) has an MnN₆ chromophore bound by six N atoms of the terminal thiocyanates. Each copper(II) centre is five coordinated by one N atom of terminal thiocyanate and four N atoms of the tripod ligand. Four copper(II) units are hydrogen bonded to form a hydrogen bonded tetramer. Each manganese(II) in turn is further engaged in hydrogen bonding to four such tetramers leading to the 3D network. Variable-temperature magnetic study shows no significant magnetic interactions among the metal ions connected by hydrogen bonding.